Historically, the conceptual base for Sun Tzu's The Art of War is the ancient Chinese concept of "yin and yang." We refer to this idea in Sun Tzu's strategy as "complementary opposites" to avoid the many conflicting cultural meanings of yinyang. Sun Tzu didn't use the yinyang terminology himself. He described his concept as "emptiness and fullness."
Since Sun Tzu's system deals specifically with competing and counterbalancing forces, it is easy to see why opposition is so important, but the idea goes deeper than that. Three basic themes underlie this concept.
- Complementary opposition is the fabric that weaves all existence. Any current situation is a temporary balance point, a stasis, representing the competing natural forces of chaos/order, matter/energy, space/time, mind/body, and all the other forces of complementary opposition.
- These competing forces generate the patterns of change. We are able to predict parts of the future because we understand the forces involved as the balance between them waxes and wanes over time. Day follows night. Booms lead to busts. Youth leads to age. Ignorance leads to knowledge.
- Finally, these forces assure the stability of nature, where an excess in one direction naturally corrects itself. The universe doesn't slip into chaos because the constant, dynamic balance of all things, naturally correct all excesses. As one force grows stronger
The earliest Chinese characters for yin and yang are found on “oracle bones” in the fourteenth century BC. In these inscriptions, they were descriptions of the climate, sunlight during the day (yang), and a lack of sunlight at night (yin). Later these ideas became associated with the division between the sun and moon, and heaven (light) and earth (dark). Over time, they began include the movement of force (chi or qi) between opposites and the physical forms of complementary opposites in nature, such as men and women.
During Sun Tzu's era, the fifth and sixth century BC, the Yinyang School of philosophy was one of the six primary schools mentioned by the historian Sima Qian. It included a number of associated sciences, such as astronomy, numbers, fortune telling, and, most importantly, wuxing, the “five phases” based on the five elements, and zhuguai, tortoise-shell divination that became associated with the Bagua. All these ideas can be traced back to the I Ching, the source work of Chinese culture.
The Zuo Zhuan (Chinese: 左傳) is the earliest Chinese work of narrative history, covering the period from the eighth to fifth centuries BC, as a commentary to the Spring and Autumn Annals, which is the period in which Sun Tzu lived. It defines the yin and yang as the first two of six heavenly forces:
There are six heavenly influences [qi] which descend and produce the five tastes, go forth in the five colors, and are verified in the five notes; but when they are in excess, they produce the six diseases. Those six influences are denominated the yin, the yang, wind, rain, obscurity, and brightness. In their separation, they form the four seasons; in their order, they form the five (elementary) terms. When any of them is in excess, they ensure calamity. An excess of the yin leads to diseases of cold; of the yang, to diseases of heat. (Legge 1994: 580)
Anyone familiar with Sun Tzu's text will note the many parallels here with his work. There is also a very similar pattern of numeric associations. Most of these many numeric patterns in Sun Tzu have complementary opposites embedded within them. The five key factors or elements are two sets of complementary opposites around a core; the six field positions are two extremes in three dimensions; and so on. This concept is critical in understanding Sun Tzu's work.
Sun Tzu taught that the natural balance in competition is maintained by these underlying opposing forces that create stable systems. We succeed in competition by leveraging these forces rather than fighting them.
Interestingly enough, Sun Tzu used the specific terms yin and yang very narrowly in his work. They describe only specific conditions of the ground. Instead, he preferred to discuss the general concept that we now call "yin and yang" in its specific tangible forms: birth/death, ground/climate, command/methods, defense/attack, nation/army, king/general, survival/destruction, and so on. When he discussed the conceptual movement of energy between two complementary opposites he used the ideas of emptiness and fullness, which we also translate as strength and weakness.
In modern terms, we can express this idea of complementary opposites in a variety of ways. When we say that nature abhors a vacuum, what goes up must go down, and that opposites attract, we are expressing the classical idea. In physics, we talk about positive and negative charges. In statistics, we talk about variation and regression to the mean. In economics, we talk about supply and demand. All these ideas and more are all part of the generic relationships of complementary opposites that are the base of Sun Tzu's Warrior's Rules.